Mad King James said:I don't think Flemish (or Fleming) is the way to go, as it was only one dialect of Old Frankish, along with Luxemberger and Brabanter, Dialects in Liege, Calais, Ypren and elsewhere.
Language is not the only consideration. I'm not very persuaded by language divisions I have never seen refered to in contemporary texts. It's ok to divide Germany into 3 or 4 sections, but then you have one problem. Germany was a linguistic continuum, those divisions had much less meaning on the periphery than "German," which is all-inclusive.
On the other hand, I am very swayed by the fact that Flemings (Flamingi) are only rarely listed as Germans (T(h)eotonici or Alemanni) in texts. Saxons for the most part are the inhabitants of the Duchy of Saxony. I needn't say that Franci refers to French by CK times. In Greek, German-Latin, French and English texts, Germans are one people; divisions amongst them were irregular, and no more meaningful than in Italy.
For the moment, Mad King James, I'm going with Flemings and Frisians. Discussion on this issue is not closed, but please believe me, I do want to get on with the maps. If some sound and managable scheme emerges, I will adopt it. In the mean time, I'm getting on with the maps.